Denture attachment



April 1963 J. L. Bl SCHOF ETAL 3,085,334

DENTURE ATTACHMENT Filed March 16. 1960 PIGS FIGS

FIG?

FIG.5

INVF/VTOKS JULIUS L. 515C110? WILMAA. POSENBACH ATTORNEY United StatesPatent 3,085,334 DENTURE ATTACHMENT Julius L. Bischof, 424i Lawn Ave,St. Louis, M0,, and

Wilma A. Dosenhach, 5324 Gladstone Ave, Normandy, Mo.

Filed Mar. 16, W60, Ser. No. 15,364 4 Claims. (Cl. 32-4) This inventionrelates to dentures generally, but more especially to the constructionof the same so that they will be accurately fitted into the mouth so asto minimize accidental displacement from their originally fittedposition.

One of the important objects of our invention is to so construct saiddenture, with an attachment means, whereby there will be little or notendency for the attached denture to rock, jump, rotate or wobble whilein the mouth.

Another object of the invention is to so construct said denture that itis easily and readily attachable and removable from a predeterminedfixed position in the mouth, with full assurance and certainty that eachsuch replacement will always position the denture in its originallyfitted position.

A further object of our invention is to so construct said dentures withattaching means, in such a way that there is a minimum of bulk that thewearer must carry in the mouth.

Other objects of the invention are to so construct such dentures thatthey will be extremely simple in construction, readily made by thedental technician, long-lasting, and which will be otherwisesatisfactory and efficient for use wherever found applicable.

Many other objects and advantages of the construction .herein shown anddescribed, and the uses for the same, -will be obvious to those skilledin the art to which the resent like or corresponding parts thoughout theviews,

FIGURE 1 is a pespective view, showing the lower jaw portion, with thedowels anchored in place therein;

FIGURE 2 is a cross-sectional detail, showing a tooth therein, cut downand having its top face planar, ready to be drilled to provide thedowel-receiving opening therein;

FIGURE 3 is an enlarged detail view of said tooth, with the dowelinserted in the same and anchored in place;

FIGURE 4 is a perspective view of the impression taken from that portionof the jaw having the dowels anchored therein, and showing a doweldetachably posi- .tioned head-end first into one of the cylindricalopenings therein made by the dowel head previously anchored in themouth;

FIGURE 5 is a model made from said impression, of the conformationindicated in FIG. 1, with one of the plastic caps removably mounted onone of the head ends of the dowels;

FIGURE 6 is an enlarged detail, showing the dowel with a cap mountedthereon; and

FIGURE 7 is a perspective view of the finished denture made to conformto said model, with the caps bonded in place therein.

Although the device hereinafter shown and described is equallyapplicable to the maxilla and the mandible portions, or to a portion ofeither, wherein it is necessary to fit a plate or denture thereto, yetthe drawings and description are directed to the mandible, for thereason that dentures therefor are usually more difficult to retain inthe mouth, on account of the relatively smaller contact area 3,085,334Patented Apr. 16, 1963 thereat between the jaw and denture, as comparedwith dentures for the maxilla.

Referring more particularly to the drawings, wherein we have illustrateda preferred embodiment of the invention, A indicates a lower jaw ormandible portion, in which there is at least one tooth structureremaining, and in this instance there are two such teeth 1-1, indicatedin dotted lines in FIG. 1, and in full lines in FIGS. 2 and 3, said pairof teeth being spaced apart laterally along the gum 4, these teeth beingintended as anchorages for permanent implacement of attachment dowels,as will be more clearly set forth.

The first step in the preparation of the mouth to receive our device, isto cut down said selected tooth or teeth to a flat or planar upper face5 to slightly below the crest or free marginal edge of the gum asindicated at 6, say to approximately .010" to .040" below said crest (asindicated in FIG. 2), exposing the root canal 7 of the tooth structures.

Then, each said root canal is drilled out to provide the cylindricalbore =18 thereinto, from said face 5, and the diameter of said bore maybe slightly in excess of the maximum diameter of the shank portion 8 ofa pin or dowel that is provided with a radially enlarged head 9,preferably cylindrical as shown, said shank being preferably tapered toits reduced free or terminal end and provided with threads or othersuitable lateral projections 10 along said tapered portion. It might beagain mentioned that it is necessary to have the depth of the bore '18at least equal to the length of the shank portion 8 of the dowel, asindicated most clearly in FIG. 3.

A shoulder, collar or flange 11 is provided intermediate the ends of thedowel, at the juncture of its shank, and head portions, said flangeprojecting radially outwardly thereat, the top and bottom faces of saidflange being flat or planar as shown.

Although said dowel may be made of any metal that will not tarnish,-rustor otherwise corrode, we have found it highly desirable that it be madeof stainless or surgical steel, as this material is not onlysufficiently sturdy and durable, is not unduly expensive, but inaddition meets all of the purposes required of it.

One of the dowels is inserted, shank-first, into one of said bored holes8, until its flange seats on the flat top face 5 of the previouslyprepared tooth, there being suitice.

.able cemetitious substance 12 in said bore. JAlthough said cemententers into the grooves or spaces between the adjacent threads of theshank portion of the dowel, this cement also fills the space betweensaid shank and the side or bounding wall of the bore hole, and in thisway more firmly anchors the dowel in its fixed intended placementrelatively of the tooth, upon setting of the cement.

Where a second tooth is employed as an anchorage, said tooth ismanipulated in the same manner as described for the first tooth, and adowel permanently set therein.

The next step is to make an impression 13, of the jaw structure havingthe dowels permanently placed therein, and this is done in any mannerthought advisable by the operator, and it is obvious that saidimpression will have the cylindrical holes, openings or recesses 14-14formed therein, of precisely the same size, contour and depth as that ofthe projecting portions of the dowels already implanted in the jaw.

Now, a model B of the jaw structure must be made, using the impressionpreviously made, to form a pattern from which the denture itself is tobe made, said model being made by the operators in any well-known mannerthat is found most convenient at the time, said resultant model beingindicated in FIG. 5 and being a workable replica of the jaw structure towhich the denture is to be applied, said model having a replica of thejaw gum structurelS', extending therealong, with a replica of the gumline or crest 16 thereon.

However, before making said model and before filling said'impressionwith-the soft materialoutof which the model is to be formed,dowels ,thatare exact replicas of those imbeddedjinthe; jaw, are,inserted head-first into the holes.14-.-14 (one such dowel being shownas already inserted in one of said holes, in FIG. 4), so that the .dowelshanks project axially above said holes. when said impression .tray orholder is filled with the .hardenable material from which the model ismade, and

Now,

compacted into place, and left to set for the required :period, and theimpression then separated from the model, it will be found that .thedowels will remain anchored in said model, as indicated in FIG. 5,inasmuch as there is algreater tendency for said threaded shanks to bondto the model materialthan for the heads to cling to said impression.Thus, it will be seen that the size, shape and spacing of the dowels inthe model will be precisely the 'same as that of the dowels inthe jawstructure itself.

Fin'ally, the operator is ready to make the denture C itself, preferablyof a suitable plastic, anacrylic resin Before performing thisstephowever, caps-19 are de- ,These caps are preferably made of a suitableplastic,

'and it has been found desirable that they be inexpandjible; for areason soon to be more clearly set forth.

Each cap has its open end flat or planar to seat perfectly on the flangeof the dowel with which it cooperates,

saidfiatend being indicated at 17, and there is a diametrally reducedneck 20 intermediate the ends of the cap.

The acrylic or'other plastic material that forms the denture is ofcourse applied while soft, to engage and cover the desired portion ofthe model, so that after the denture material has set andthe denturethen removed from said model, said caps will be found to have becomepermanently anchored in the denture, and spaced apart to correspondprecisely to the spacingapart of the dowels firstimplanted into the jaw.

. One-of theimportant reasons formaking the cap of a plastic materialisv such material has a betterv bonding quality to the plastic of thedenture itself, than if the two elementswere of different materials,.andthere is practically no likelihood of any displacement of the capsfrom their anchorage in-the denture. Further, the plastic cap will havea minimum of friction withthe dowelhead,

.' thereby resulting in a minimum of wearbetween said .parts.

'being extremely suitable for'the purpose, from said model that alreadyhas said dowels anchored therein.

5O 7 first into said recess, making a model from said impression wherebythe dowelheld in the impression becomes No matter how many times thedenture is replaced,

there is assurance that it will have a perfect cooperating fitbetween'the caps and dowels, thus maintaining exact relative positioningin the mouth and with consequent 'goodstabilization of the denture, withno lateral rotation of the denture when mounted;- and no possibility ofthe implanted dowels and that might result in said denture becomingjumpy or have other defects of an ill-fit.

Inasmuch as the interfitting dowels and caps are cylindrical at theircooperating portions, with substantiallya minimum tolerancetherebetween, there is less likelihood of food particles getting intosaid cooperating portions, than if there was a yieldably resilientinterconnection between said elements, as in our devicethe cooperatingelements must that each replacement. and there is no danger ofdistortion of either element due to accidental springing of the parts.

Weclaim: I l

1. A detachable artificial vdenture means comprising a .dowelpermanently anchorableinthemouth and having ,an elongated shank with aheadatone. end, said head .being of substantially same cross-sectionalarea throughout, the shank anchorable in atooth-root canal so that saidheadwill project outwardly beyondsaid canal, a

.denture, anda. cup-shaped: recessedv cap. permanently .anchored in saiddenture with .the depth .and diameter of said recess of the cap .beingoftfixed size substantially 'tlange seatable on the top-face ofsaid:tooth.

3. Detachable artificial 'denture means comprising a;

pair of metal dowels to'be permanently anchored in laterallyspaced-apart relation in the mouth,.-.ea'ch-dowel having anelongatedshank with'a radially 'enlarged subj 'stantially cylindrical head atoneend, to be anchored in a tooth root canal and a denture for'fittingthat portion of the mouth thathas said dowelstherein, and a pairof hollow cup-shaped caps permanently anchored in said denture andspaced apart to conform exactly to the spacing between said dowels andsaid'caps having'su-bstantially cylindrical recesses of such depth anddiameter to snuglyreceive the dowel heads substantially without lateralmovement therebetween, the exterior of said cap provided with adiametrally reduced neck'intermediate its ends to form an annular grooveto receive the material of said denture therein and interlock therewith.

4. In the method of preparing a removable artificial denture, the stepsof anchoring a'metal dowel in a tooth 'in the mouth so that the head ofsaid dowel projects permanently above said tooth, then making animpression whereby said projecting portion of thedowel forms a recess inthe impression, inserting a metal dowel exactly of the size and shapeasthe first-mentioned dowel, headanchored in said model upon separationof the model from the impression, placing a plastic cap removably on thedowel that is in the model, makinga plastic denture to fit over saidmodelas so capped, whereby said cap remains anchored in the denture onsetting of'the latter and removal from the model, and finally removingsaid denture from the model.

References Cited in the file of'this patent UNITEDSTATES PATENTS 581,335Carr Apr. 27, 1897 711,324 Lacy Oct. 14, 1902 2,112,007 Adams Mar. 22,1938

1. A DETACHABLE ARTIFICIAL DENTURE MEANS COMPRISING A DOWEL PERMANENTLYANCHORABLE IN THE MOUTH AND HAVING AN ELONGATED SHANK WITH A HEAD AT ONEEND, SAID HEAD BEING OF SUBSTANTIALLY SAME CROSS-SECTIONAL AREATHROUGHOUT, THE SHANK ANCHORABLE IN A TOOTH-ROOT CANAL SO THAT SAID HEADWILL PROJECT OUTWARDLY BEYOND SAID CANAL, A DENTURE, AND A CUP-SHAPEDRECESSED CAP PERMANENTLY ANCHORED IN SAID DENTURE WITH THE DEPTH ANDDIAMETER OF SAID RECESS OF THE CAP BEING OF FIXED SIZE SUBSTANTIALLYCOMPLEMENTAL TO SAID PROJECTING PORTION OF SAID DOWEL HEAD AND SNUGLYRECEIVING SAID DOWEL HEAD.